Illinois Compiled Statutes (Tax)

35 ILCS 105/8 — Any retailer required to collect the tax imposed by this Act shall be liable to the Department for such tax, whether or not the tax has been collected by the retailer, except when the retailer is relieved of the duty of remitting the tax to the Department by virtue of having paid a tax imposed by the Retailers' Occupation Tax Act upon his or her gross receipts from the same transactions

Source: official text